Share 'Win a free signed copy of Michael Shermer's new book The Believing Brain!!'

***UPDATE: The contest is LIVE now. Remember, to enter the contest you must be a member of Think Atheist, you must follow Think Atheist on Twitter, and you must tweet the following: "I'm a member of @ThinkAtheist and I want a copy of @michaelshermer's "The Believing Brain"! bitly.com/lF1bBd #atheism #atheist #skeptic".Your best bet is to copy and paste the tweet (without the quotation marks of c…